U.S. patent application number 11/526387 was filed with the patent office on 2008-03-27 for apparatus for producing helically corrugated metal pipe and related method.
Invention is credited to James C. Schluter, William L. Zepp.
Application Number | 20080072642 11/526387 |
Document ID | / |
Family ID | 39223464 |
Filed Date | 2008-03-27 |
United States Patent
Application |
20080072642 |
Kind Code |
A1 |
Zepp; William L. ; et
al. |
March 27, 2008 |
Apparatus for producing helically corrugated metal pipe and related
method
Abstract
A pipe manufacturing system and method for producing helically
corrugated metal pipe is provided. The system and method utilize
controlled profile formation.
Inventors: |
Zepp; William L.;
(Maineville, OH) ; Schluter; James C.; (Franklin,
OH) |
Correspondence
Address: |
THOMPSON HINE L.L.P.;Intellectual Property Group
P.O. BOX 8801
DAYTON
OH
45401-8801
US
|
Family ID: |
39223464 |
Appl. No.: |
11/526387 |
Filed: |
September 25, 2006 |
Current U.S.
Class: |
72/49 |
Current CPC
Class: |
B21C 37/124 20130101;
B21C 37/121 20130101 |
Class at
Publication: |
72/49 |
International
Class: |
B21C 37/12 20060101
B21C037/12 |
Claims
1. A pipe manufacturing apparatus, comprising: (a) a decoiler unit
for receiving a coil formed by a rolled metal sheet, the decoiler
unit permitting the coil to rotate; (b) a corrugating line for
drawing the metal sheet off of the coil and placing corrugations in
the metal sheet to produce a corrugated metal strip, the
corrugating line comprising: (i) a first tooling stand configured
to receive flat sheet material and to produce a first wave-shaped
cross-sectional profile in the sheet, where upper and lower crests
of the first wave-shaped cross-sectional profile are generally
curved and lack any flats or small radius bends; (ii) a second
tooling stand downstream of the first tooling stand and configured
to modify the first wave-shaped cross-sectional profile so as to
produce a second wave-shaped cross-sectional profile, where upper
and lower crests of the second wave-shaped cross-sectional profile
are generally curved and lack any flats or small radius bends, and
a height of the second wave-shaped cross-sectional profile is
greater than a height of the first wave-shaped cross-sectional
profile; and (iii) multiple tooling stands downstream of the second
tooling stand for completing formation of multiple box-shaped
corrugations in the metal sheet to form a corrugated metal strip in
which the spacing between box-shaped corrugations along the width
of the strip is substantially greater than the box-shaped
corrugation width, each box-shaped corrugation including a
generally flat bottom portion and upwardly extending parallel side
portions; (c) a forming head positioned to receive the corrugated
metal strip and to spiral the corrugated metal strip into a
pipe-shape.
2. The pipe manufacturing apparatus of claim 1 wherein the
corrugating line further includes a drive stand formed by opposed
pinch rollers, the drive stand located upstream of the first
tooling stand.
3. A pipe manufacturing apparatus, comprising: (a) a decoiler unit
for receiving a coil formed by a rolled metal sheet, the decoiler
unit permitting the coil to rotate; (b) a corrugating line for
drawing the metal sheet off of the coil and placing corrugations in
the metal sheet to produce a corrugated metal strip, the
corrugating line comprising: (i) a first tooling stand configured
to receive flat sheet material and to produce a first wave-shaped
cross-sectional profile in the sheet, where upper and lower crests
of the first wave-shaped cross-sectional profile are generally
curved and lack any flats or small radius (ii) a second tooling
stand downstream of the first tooling stand and configured to
modify the first wave-shaped cross-sectional profile so as to
produce a second wave-shaped cross-sectional profile, where upper
and lower crests of the second wave-shaped cross-sectional profile
are generally curved and lack any flats or small radius bends, and
a height of the second wave-shaped cross-sectional profile is
greater than a height of the first wave-shaped cross-sectional
profile; (iii) multiple tooling stands downstream of the second
tooling stand for completing formation of multiple box-shaped
corrugations in the metal sheet to form a corrugated metal strip,
the multiple tooling stands including: (1) a third tooling stand
downstream of the second tooling stand and configured to modify the
second wave-shaped cross-sectional profile so as to produce a third
wave-shaped cross-sectional profile, upper and lower crests of the
third wave-shaped cross-sectional profile are generally curved and
lack any flats or small radius bends, a height of the third
wave-shaped cross-sectional profile is greater than the height of
the second wave-shaped cross-sectional profile; (2) a fourth
tooling stand downstream of the third tooling stand and configured
to modify the third wave-shaped cross-sectional profile so as to
produce a fourth wave-shaped cross-sectional profile having upper
crests that are generally curved and lower crests that are
generally flat, a height of the fourth wave-shaped cross-sectional
profile is less than the height of the third wave-shaped
cross-sectional profile. (iv) a drive stand formed by opposed pinch
rollers, the drive stand located upstream of the first tooling
stand; and (c) a forming head positioned to receive the corrugated
metal strip and to spiral the corrugated metal strip into a
pipe-shape.
4. The pipe manufacturing apparatus of claim 3 wherein the multiple
tooling stands of (b)(iii) further include: (4) a fifth tooling
stand downstream of the fourth tooling stand and configured to
modify the fourth wave-shaped cross-sectional profile so as to
produce a fifth wave-shaped cross-sectional profile having upper
crests that are generally curved and lower crests that are
generally flat with small radius corners at edges thereof, a height
of the fifth wave-shaped cross-sectional profile is less than the
height of the fourth wave-shaped cross-sectional profile; (5) a
sixth tooling stand downstream of the fifth tooling stand and
configured to modify the fifth wave-shaped cross-sectional profile
so as to produce a sixth wave-shaped cross-sectional profile having
upper crests that are generally flat and lower crests that are
generally flat, a height of the sixth wave-shaped cross-sectional
profile is less than the height of the fifth wave-shaped
cross-sectional profile; (6) one or more additional tooling stands
for modifying side edges of the sheet to create lock seaming
lips.
5. The pipe manufacturing apparatus of claim 4 wherein a distance
between centers of the lower crests of the fourth wave-shaped
cross-sectional profile is the same as both (i) a distance between
centers of the lower crests of the fifth wave-shaped
cross-sectional profile and (ii) a distance between centers of the
lower crests of the sixth wave-shape cross-sectional profile.
6. The pipe manufacturing apparatus of claim 4 wherein the sixth
wave-shaped cross-sectional profile includes box-shaped
corrugations that form the lower crests, and the sixth tooling
stand includes a rotating upper tooling assembly having first
portions that ride within the box-shaped corrugations and second
portions that engage the upper crests, the first portions are
driven by a slip-clutch arrangement with respect to the second
portions to permit relative movement between the first portions and
the second portions so as to reduce sliding of the first portions
relative to the box-shaped corrugations.
7. A pipe manufacturing apparatus, comprising: (a) a decoiler unit
for receiving a coil formed by a rolled metal sheet, the decoiler
unit permitting the coil to rotate; (b) a corrugating line for
drawing the metal sheet off of the coil and placing corrugations in
the metal sheet to produce a corrugated metal strip, the
corrugating line comprising: (i) at least one tooling stand that
produces a flat-free wave-shaped cross-sectional profiles having
respective upper and lower crests that are generally curved and
lack any flats or small radius bends; (ii) a first tooling stand
downstream of the at least one tooling stand and configured to
modify the flat-free wave-shaped cross-sectional profile so as to
produce a first flat-inclusive wave-shaped cross-sectional profile
having upper crests that are generally curved and lower crests that
are generally flat; (iii) a second tooling stand downstream of the
first tooling stand and configured to modify the first
flat-inclusive wave-shaped profile so as to produce a second
flat-inclusive wave-shaped profile having upper crests that are
generally curved and lower crests that are generally flat, where a
height of the second flat-inclusive wave-shaped cross-sectional
profile is less than a height of the first flat-inclusive
wave-shaped cross-sectional profile, wherein a distance between
centers of the lower crests of the second flat-inclusive
wave-shaped cross-sectional profile is the same as a distance
between centers of the lower crests of the first flat-inclusive
wave-shaped cross-sectional profile; (iv) at least one tooling
stand downstream of the second tooling stand for completing
formation of multiple box-shaped corrugations in the metal sheet to
form a corrugated metal strip; (c) a forming head positioned to
receive the corrugated metal strip and to spiral the corrugated
metal strip into a pipe-shape.
8-11. (canceled)
12. The pipe manufacturing apparatus of claim 7 wherein the at
least one tooling stand downstream of the second tooling stand
includes a tooling stand with a rotating upper tooling assembly
having first portions that ride within the box-shaped corrugations
and second portions that engage the upper crests, the first
portions are driven by a slip-clutch arrangement with respect to
the second portions to permit relative movement between the first
portions and the second portions so as to reduce sliding of the
first portions relative to the box-shaped corrugations.
Description
TECHNICAL FIELD
[0001] This application relates generally to helically corrugated
metal pipe commonly used in drainage applications and, more
specifically, to an apparatus for effectively producing such pipe
utilizing polymer coated steel.
BACKGROUND
[0002] The standard production process for producing helically
corrugated metal pipe is well known and involves first forming
lengthwise corrugations in an elongated strip of sheet metal, with
the corrugations extending along the length of the strip. The
corrugated strip is then spiraled into a helical form so that
opposite edges of the corrugated strip come together and can be
either crimped (commonly referred to as lock seaming) or welded to
form a helical lock along the pipe.
[0003] U.S. Pat. No. 4,791,800 to Alexander describes a roll
forming process for making box-shaped ribs in a sheet material,
such as steel, utilizing a series of tooling stands through which
the sheet material is moved. The system of U.S. Pat. No. 4,791,800
typically includes additional tooling stands to further flatten the
curved areas of the strip (shown in FIG. 4 of U.S. Pat. No.
4,791,800) and to form edges for lock seaming.
SUMMARY
[0004] A system and method for producing helically corrugated metal
pipe is provided using progressive profile formation that is more
suited to producing a higher quality pipe product.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a top plan schematic of a pipe manufacturing
device;
[0006] FIG. 2 is a cross-section of an exemplary corrugated metal
strip taken along line 2-2 of FIG. 1;
[0007] FIG. 3 is an exemplary cross-section of a lockseam; and
[0008] FIGS. 4A-4I depict embodiments of the tooling stands that
form the corrugated metal strip; and
[0009] FIG. 5 depicts a tooling cross-section showing a slip-clutch
arrangement.
DETAILED DESCRIPTION
[0010] Referring to FIG. 1, a pipe manufacturing line or device 10
is shown in top plan schematic form. The device 10 includes a
decoiler unit 12 for receiving a coil 14 formed by a rolled metal
sheet (which may or may not include a galvanized coating or a
polymeric coating). The illustrated decoiler unit 12 supports the
coil 14 on a rotatable expansion mandrel 16, permitting the coil to
rotate during pipe manufacture. A weld table 18 is shown downstream
of the decoiler unit 12 and is provided for welding the end of one
metal sheet to the end of the metal sheet of a different coil upon
coil replacement. A corrugating line 20 includes a pinch roll 22
for drawing the metal sheet off of the coil 14 and feeding the
sheet through a number of tooling stands 24 (A thru I) that form
box-shaped corrugations in the metal sheet to produce a corrugated
metal strip 26. As will be described in greater detail below, the
metal sheet passes between upper and lower tooling structure in
each of the stands 24 to form corrugations. In one embodiment, the
pipe manufacturing device operates to produce hydraulically
efficient pipe such as that described in U.S. Pat. No. 4,838,317,
in which case the corrugated metal strip may have a cross-section
similar to that generally shown in FIG. 2, where the corrugations
11 are shown with a generally rectangular or box-shape and the side
edges of the corrugated metal strip 26 include respective lips 13
and 15 for use in producing the helical lockseam described below.
The exact configuration of locking lips 13 and 15 can vary.
[0011] The rotational tooling of the illustrated tooling stands may
be driven by an electric motor 28 with its output linked to a
gearbox/transmission arrangement 30. Multiple motors and gearboxes
could also be provided. A forming head 32 is positioned to receive
the corrugated metal strip 26 and includes a lockseam forming
mechanism (not shown). The forming head 32 may be a well known
three-roll forming head configured to spiral the corrugated metal
strip 26 back upon itself as shown. The lockseam mechanism locks
adjacent edges of the spiraled corrugated metal strip in a crimped
manner to produce a helical lockseam 100 in the resulting pipe 102.
Specifically, as the corrugated metal strip is helically curved
back upon itself to form the pipe-shape, the locking lips 13 and 15
come together before passing into the lockseam mechanism, and the
lockseam mechanism presses the lips together to produce a lockseam
that may, in one example, have the general appearance of that shown
in the cross-section of FIG. 3. In an alternative embodiment a weld
arrangement could be provided to weld together the adjacent edges
of the corrugated metal strip when they come together during
spiraling.
[0012] Referring back to FIG. 1, a saw unit 34 is positioned along
the pipe exit path and includes a saw 36 that is movable into and
out of engagement with the pipe 102 and that is also movable along
a path parallel to the pipe exit path so that the pipe can be cut
even while pipe continues to be produced. Pipes with a variety of
diameters can be formed by the device 10, and large scale diameter
control is made by adjusting an entry angle of the corrugated metal
strip 24 to the forming head 32. Such angle adjustment can be
achieved by either by rotating the forming head 32 relative to a
stationary corrugation line 20 or by rotating the corrugation line
20, weld table 18 and decoiler unit 12 relative to a stationary
forming head 32.
[0013] Referring now to FIGS. 4A-4I, the configuration of the
tooling of stands 24 is described along with the progressive
profile each stand produces in the metal sheet.
[0014] FIG. 4A reflects tooling stand 24A, which receives the flat
metal sheet from drive stand 22 and modifies the flat profile to
produce the wave-shaped cross-sectional profile 50 (shown in
cross-section) in the sheet, where upper 52 and lower 54 crests of
the wave-shaped cross-sectional profile 50 are generally curved and
lack any flats or small radius bends. As used herein, the term
"small radius bends" means a bend having a radius that less than
three times the thickness of the metal sheet that is being
corrugated. Axes of rotation for the upper and lower tooling are
shown respectively at 56A and 56B. Center lines of the lower crests
of the profile are shown at 58.
[0015] FIG. 4B reflects tooling stand 24B, which receives the
profile 50 and modifies it to produce a wave-shaped cross-sectional
profile 60, where upper 62 and lower 64 crests of the
cross-sectional profile 60 are generally curved and lack any flats
or small radius bends. A height H60 of the wave-shaped
cross-sectional profile 60 is greater than a height H50 of the
wave-shaped cross-sectional profile 50. As used herein the "height"
of each cross-sectional profile is determined by the vertical
distance between the top of an upper crest and the bottom of a
lower crest. Axes of rotation for the upper and lower tooling are
shown respectively at 66A and 66B. Center lines of the lower crests
of the profile are shown at 68.
[0016] FIG. 4C reflects tooling stand 24C, which receives the
profile 60 and modifies to produce a wave-shaped cross-sectional
profile 70, where upper 72 and lower 74 crests of the wave-shaped
cross-sectional profile 70 are generally curved and lack any flats
or small radius bends. A height H70 of the wave-shaped
cross-sectional profile 70 is greater than the height H60 of the
wave-shaped cross-sectional profile 60. Axes of rotation for the
upper and lower tooling are shown respectively at 76A and 76B.
Center lines of the lower crests of the profile are shown at
78.
[0017] FIG. 4D reflects tooling stand 24D, which receives the
profile 70 and modifies it so as to produce a wave-shaped
cross-sectional profile 80 having upper crests 82 that are
generally curved and lower crests 84 that are generally flat. A
height H80 of the wave-shaped cross-sectional profile 80 is less
than the height H70 of the wave-shaped cross-sectional profile 70.
Axes of rotation for the upper and lower tooling are shown
respectively at 86A and 86B. Center lines of the lower crests of
the profile are shown at 88.
[0018] FIG. 4E reflects tooling stand 24E, which receives the
profile 80 and modifies it so as to produce a wave-shaped
cross-sectional profile 90 having upper crests 92 that are
generally curved and lower crests 94 that are generally flat with
small radius corners 96 at edges thereof. A height H90 of the
wave-shaped cross-sectional profile 90 is less than the height H80
of the wave-shaped cross-sectional profile 80. Axes of rotation for
the upper and lower tooling are shown respectively at 97A and 97B.
Center lines of the lower crests of the profile are shown at
98.
[0019] FIG. 4F reflects tooling stand 24F, which receives the
profile 90 and modifies it so as to produce a wave-shaped
cross-sectional profile 110 having upper crests 112 that are
generally flat and lower crests 113 that are generally flat with
small radius corners. A height H110 of the wave-shaped
cross-sectional profile 110 is less than the height H90 of the
wave-shaped cross-sectional profile 90. At this point the formation
of the box corrugations 115 is completed, and the remaining tooling
stands simply modify the sheet edges to facilitate later formation
of the lockseam as described above. Notably, the upper assembly 116
of tooling stand 24F is formed in a manner such that portions 118
that ride within the box-shaped corrugations 115 are driven by a
slip-clutch arrangement (depicted by dashed area 120) with respect
to the portions 122 of the assembly 116 that engage the upper
crests 112. Referring to the partial cross-section of FIG. 5, the
slip clutch arrangement may be achieved using a drive shaft 150
that is keyed to move an annular segment 152. Engagement between
the outer surface of segment 152 and the inner surface of portion
118 causes the rotation of portion 118. This arrangement permits
relative movement between the portions 118 and the segments 152,
and thus tooling portions 122, when the frictional force between
the two surfaces is overcome, thereby reducing the sliding of the
portions 118 relative to the box-shaped corrugations 115. This
feature is particularly advantageous for working polymer coated
metal sheet as it reduces tearing of the polymer that can occur
during sliding of portions 118 relative to the polymer. Axes of
rotation for the upper and lower tooling are shown respectively at
117A and 117B. Center lines of the lower crests of the profile are
shown at 119.
[0020] Referring to FIGS. 4G, 4H and 4I, it is noted that the
central portion of each depicted tooling stand 24G, 24H and 24I is
identical to that of stand 24F, inclusive of the described slip
clutch driving of portions 118. Accordingly, in FIGS. 4g, 4H and 4I
only the end portions of the stands are shown to depict the sheet
edge modification for lockseaming.
[0021] Referring back to FIGS. 4A and 4B, the distance between
center lines 58 in profile 50 may be slightly larger than the
distance between center lines 68 in profile 60. In one embodiment,
the distance between centerlines 68 in profile 60 is the same as
the distance between centerlines 78, 88, 98 and 119 in respective
profiles 70, 80, 90 and 110.
[0022] By utilizing initial tooling stands that gather the metal
more slowly than that of the prior art, and that do not immediately
attempt to form flats and corresponding small radius bends, the
integrity of the metal sheet and any coating (polymer or otherwise)
thereon is better maintained, producing a better quality end
product. In the past, it has not been commercially viable to form
helical pipe of the type described using polymer coated gauges of
14 or higher due to the resulting polymer damage and the labor
involved in repairing such damage. Using the tooling system and
method described above, such polymer damage can be significantly
reduced, making the production of 14, 12 and even 10 gauge
helically corrugated polymer coated metal pipe commercially viable.
It may be possible to achieve a surface area polymer defect rate
that is less than about 2% of total polymer surface area.
[0023] It is to be clearly understood that the above description is
intended by way of illustration and example only and is not
intended to be taken by way of limitation, and that changes and
modifications are possible. Accordingly, other embodiments are
contemplated.
* * * * *